Gravity flow incinerator

ABSTRACT

A gravity flow incinerator for burning refuse, trash, and industrial wastes, etc. including an upright vertical chamber having grates vertically spaced throughout the height of the unit. Each grate is inclined downwardly and inwardly towards a central opening. Air is fed to each of the openings through the grate itself. The central openings in the grates are progressively smaller from the uppermost grate to the lowermost grate. The residue leaving the vertical incinerator is fed to a rotary incinerator where combustion is completed.

United States Patent [1'91 Polsak July 16, 1974 [54] GRAVITY FLOW INClNERATOR 1,861,135 2/1322 \RJ'lrey 110/7 X 1,957,921 1 4 Inventor: Edwin Mark Polsak, South EuClld, 3 4 9 527 $1970 c Jr et al 0/14 Ohio I [73] Assignee: Combustion Engineering, Inc., Primary Examiner-Kenneth W. Sprague Windsor, Conn. Attorney, Agent, or Firm-Robert L. Olson [22] Filed: Dec. 15, 1972 21 Appl. No.: 315,742 [571 A T Y A gravity flow incinerator for burning refuse, trash, and industrial wastes, etc. including an upright vertical 110/8 3311241 21 Chamber having grates vertically Spacedvthmughout [58] Fieid 8 8 B the height of the unit. Each grate is inclined down- C l 8 R 8 18 v wardly and inwardly towards a central opening. Air is fed to each of the openings through the grate itself. I The central openings in the grates are progressively [56] References Cited smaller from the uppermost grate to the lowermost UNITED STATES PATENTS grate. The residueleaving the vertical incinerator is 895,129 8/1908 Van Doren 110/8 fed to a rotary incinerator where combustion is com- 1,091,837 3/1914 Haskin 110/8 x pleted. r 1,235,918 8/1917 Nieberding 110/18 1,776,914 4 Claims, 2 Drawing Figures 9/1930 Langford ..110/18 1 GRAVITY FLOW INCINERATOR BACKGROUND OF THE INVENTION The disposal of trash and refuse has been of growing concern to many in current times. One method of disposing of these solid wastes is to burn it in an incinerator. Because of the variations in size and type of material encountered in trash and refuse, the complete burning of all the solid wastes in the fastest and most economical manner presents a problem. One manner of overcoming the size problem is to shred all of the solid wastes prior to burning it in an incinerator. Because of the large pieces of metal, glass, wood and other dense items contained in trash, the shredder is a piece of equipment with'a large initial cost that will require continued maintenance.

SUMMARY-OF THE INVENTION The gravity flow incinerator of the present invention includes an upright vertical chamber having a plurality of vertically spaced grates, each having walls inclined downwardly towards a central opening therein. The

' openings are progressively smaller from the uppermost grate to the lowermost grate. The residue'leaving the bottom of the vertical incinerator is fed to a rotary incinerator where the combustion of all the solid waste is completed. The major portion of the trash and refuse is burned in the vertical incinerator.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross sectional side view of an incinerator arrangement constructed in accordance with the invention; and

FIG. 2 is a sectional view taken on lines 22 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT 18 and 20 are progressively smaller from the upper-' most grate to the lowermost grate. A pilot burner 22 positioned beneath the lowest grate is used for initial combustion of the solid wastes, and can also be used for re-ignition if the fire goes out for some reason.

The residue falling through opening 20 in the lowest grate l4 slides down an inclined chute 24 into a rotary incinerator 26. Here the harder to burn and slow burning wastes, such as large pieces of wood, are completely 1 combusted in the rotating chamber. The combustion gases are exhausted from the .rotary incinerator through exhaust passage 28. If desired, an afterburner, wet scrubber, and other gas cleaning equipment can and usually will be contained in the exhaust system to. minimize air pollution. The exhaust duct 30 leading from the upper portion of the vertical incinerator discharges combustion gases into the exhaust system of the rotary incinerator 26, so that duplication of gas cleaning equipment is not necessary.

Combustion air is supplied to each of the grates 14 in the vertical incinerator by way of a plurality of pas- 2 sages '36 which extend radially through each grate (FIG. 2). The air is discharged into each of the central openings l6, l8 and 20. Air fan 32 supplies air to the passages 36 through manifold ducts 34 which encircle the incinerator 10 at each grate elevation.

From the above, it can be seen that an incineration system is provided which has a number of advantages. The series of grates having progessively smaller openings-allows wastes to fall by gravity from one level to the next as particle sizes are reduced by combustion. The structure forms an automatic self-regulating feed mechanism from one grate level to the next by which the combustion rate governs the rate of flow of waste through the openings in the grates. Periodic supply of material from the hopper 12 is provided by. opening gate 13. Good agitation of the burning waste is provided as the wastes fall, tumble, and break apart as it drops from one grate to the next. This exposes new surfaces' of the waste material to the oxygen laden air introduced to the central opening of each g'rate,resulting in burning at accelerated rates. The air in passing through the refractory grates also performs the function of cooling these grates 14. The vertical distance between grates is sufficient to create drop zones,

causing good agitation of the waste material. This allows rapidreduction of organic wastes without a need for mechanical agitation. The present incinerator has both a low initial installation cost and a low maintenace cost per pound of refuse incinerated.

The small sized particles of trash and refuse, such as cardboard, paper, plastics and'small wood items will be burned in the vertical incinerator. Large items, such as magazines or paper wired into bundles, and large wooden members that require long combustion times, will be only partially combusted in the vertical incinerator. The burning process of these items will be com- .pleted in the rotary incinerator.

What is claimed is:

1. In combination a vertical incinerator for burning refuse including vertical wall means forming an upright chamber, a plurality of vertically spaced grates positioned within the chamber, each grate having an inclined upper surface which extends downwardly from its outer edge, the entire outer periphery thereof being secured to the vertical wall means around its entire periphery, each grate having a central opening therein, .the openings of the grates being progressively smaller from the uppermost grate to the lowermost grate, the openings in all of the grates being sufficiently small so that some refuse becomes wedged within the opening of each grate, and is supported 'bythe grate until sufficient combustion takes place to reduce the refuse particle size sufficiently to allow it to drop onto the next lower grate, each of the grates being spaced vertically an amount which allows tumbling and agitation of the refuse as it falls to a lower grate, thereby increasing the combustion efficiency.

2. The combination set forth in claim I, including a plurality of radial passageways in each grate, an air supply source, each passageway having an inlet end connected to the air supply source and an outlet connected to the central opening in the grate.

3. The combination set forth inclaim 1, including a rotary incinerator, and conveying means extending from beneath the opening of the lowermost grate to the rotary incinerator.

4. The combination set forth in claim 3 wherein the rotary incinerator has an exhaust duct, and the vertical incinerator has an exhaust duct, the exhaust duct of the vertical incinerator having an inlet end connected to the upper portion of the upright chamber, and an outlet connected to the exhaust duct of the rotary incinerator. l =l 

1. In combination a vertical incinerator for burning refuse including vertical wall means forming an upright chamber, a plurality of vertically spaced grates positioned within the chamber, each grate having an inclined upper surface which extends downwardly from its outer edge, the entire outer periphery thereof being secured to the vertical wall means around its entire periphery, each grate having a central opening therein, the openings of the grates being progressively smaller from the uppermost grate to the lowermost grate, the openings in all of the grates being sufficiently small so that some refuse becomes wedged within the opening of each grate, and is supported by the grate until sufficient combustion takes place to reduce the refuse particle size sufficiently to allow it to drop onto the next lower grate, each of the grates being spaced vertically an amount which allows tumbling and agitation of the refuse as it falls to a lower grate, thereby increasing the combustion efficiency.
 2. The combination set forth in claim 1, including a plurality of radial passageways in each grate, an air supply source, each passageway having an inlet end connected to the air supply source and an outlet connected to the central opening in the grate.
 3. The combination set forth in claim 1, including a rotary incinerator, and conveying means extending from beneath the opening of the lowermost grate to the rotary incinerator.
 4. The combination set forth in claim 3 wherein the rotary incinerator has an exhaust duct, and the vertical incinerator has an exhaust duct, the exhaust duct of the vertical incinerator having an inlet end connected to the upper portion of the upright chamber, and an outlet connected to the exhaust duct of the rotary incinerator. 